If you've ever had a dog, you know the signature canine "guilty look": ears back, head cowered, tail tucked.

Seventy-four percent of dog owners believe their dogs experience guilt, but animal behaviorists say dogs lack the ability to feel shame. They say that guilty look is simply a reaction to you.

While there's plenty of evidence that man's best friend experiences primary emotions, such as fear and happiness, there's little evidence that dogs feel secondary emotions like pride, jealousy and guilt.

Scientist say this is because secondary emotions require self-awareness and a level of cognition that dogs may not have.

Alexandra Horowitz, a psychology professor and principal investigator at the Horowitz Dog Cognition Lab at Columbia University, conducted one of the first studies on dog "guilt" in 2009.

She videotaped 14 dogs in a series of trials and observed how they reacted when their owners left the room after instructing them not to eat a treat. While the owner was gone, Horowitz gave some of the dogs the forbidden treat before asking the owners back in.

In some cases the owners were told their dog had eaten the treat, but in others, they were told their dog had behaved. However, Horowitz wasn't always honest with them.

Horowitz found that the dogs' guilty looks had little to do with whether they'd eaten the treat or not. In fact, dogs that hadn't eaten it but were scolded by misinformed owners tended to exhibit the most elements of the "guilty look."

Horowitz says this shows that the dogs' body language is actually a response to their owner’s behavior — not an experience of shame for a misdeed.

"The 'guilty look' would be better called the 'submissive look,' as in, 'Don’t punish me for whatever it is you think I did,'" Horowitz wrote in The Washington Post.

Why then, do dogs look so ashamed when we scold them?

That look of guilt is likely the result of a learned association. When you scold your dog for chewing a pair of slippers or leaving a mess on the carpet, he quickly learns that if he lowers his head and tucks his tail, the undesirable response — raised voice and angry expression — is more likely to cease.

Almost 60 percent of dog owners claim that their dogs' guilty behavior leads them to scold their dog less, according to a study by Universities Federation for Animal Welfare.

Still, scientific findings haven't deterred the popularity of websites like DogShaming.com where dog owners submit photos of their disorderly dogs with humorous confessions.

"I don't think dogs actually feel shame," Pascale Lemire, creator of the website, told The Associated Press. "I think they know how to placate us with this sad puppy-dog look that makes us think they're ashamed of what they've done.

"My guess is that their thinking is: 'Oh man, my owner is super mad about something, but I don't know what, but he seems to calm down when I give him the sad face, so let's try that again.'"